a85b5759f3
These files were pulled from the 1.6.3 release tarball. This new version builds against OpenSSL version 1.1 which will be the default in the new Debian Stable which is due to be released RealSoonNow (tm).
193 lines
6.2 KiB
C
193 lines
6.2 KiB
C
/*
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* rbtree.h -- generic red-black tree
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*
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* Copyright (c) 2001-2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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/**
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* \file
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* Red black tree. Implementation taken from NSD 3.0.5, adjusted for use
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* in unbound (memory allocation, logging and so on).
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*/
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#ifndef UTIL_RBTREE_H_
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#define UTIL_RBTREE_H_
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/**
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* This structure must be the first member of the data structure in
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* the rbtree. This allows easy casting between an rbnode_type and the
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* user data (poor man's inheritance).
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*/
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typedef struct rbnode_type rbnode_type;
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/**
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* The rbnode_type struct definition.
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*/
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struct rbnode_type {
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/** parent in rbtree, RBTREE_NULL for root */
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rbnode_type *parent;
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/** left node (smaller items) */
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rbnode_type *left;
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/** right node (larger items) */
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rbnode_type *right;
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/** pointer to sorting key */
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const void *key;
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/** colour of this node */
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uint8_t color;
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};
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/** The nullpointer, points to empty node */
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#define RBTREE_NULL &rbtree_null_node
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/** the global empty node */
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extern rbnode_type rbtree_null_node;
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/** An entire red black tree */
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typedef struct rbtree_type rbtree_type;
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/** definition for tree struct */
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struct rbtree_type {
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/** The root of the red-black tree */
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rbnode_type *root;
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/** The number of the nodes in the tree */
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size_t count;
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/**
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* Key compare function. <0,0,>0 like strcmp.
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* Return 0 on two NULL ptrs.
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*/
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int (*cmp) (const void *, const void *);
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};
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/**
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* Create new tree (malloced) with given key compare function.
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* @param cmpf: compare function (like strcmp) takes pointers to two keys.
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* @return: new tree, empty.
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*/
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rbtree_type *rbtree_create(int (*cmpf)(const void *, const void *));
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/**
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* Init a new tree (malloced by caller) with given key compare function.
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* @param rbtree: uninitialised memory for new tree, returned empty.
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* @param cmpf: compare function (like strcmp) takes pointers to two keys.
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*/
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void rbtree_init(rbtree_type *rbtree, int (*cmpf)(const void *, const void *));
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/**
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* Insert data into the tree.
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* @param rbtree: tree to insert to.
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* @param data: element to insert.
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* @return: data ptr or NULL if key already present.
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*/
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rbnode_type *rbtree_insert(rbtree_type *rbtree, rbnode_type *data);
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/**
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* Delete element from tree.
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* @param rbtree: tree to delete from.
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* @param key: key of item to delete.
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* @return: node that is now unlinked from the tree. User to delete it.
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* returns 0 if node not present
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*/
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rbnode_type *rbtree_delete(rbtree_type *rbtree, const void *key);
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/**
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* Find key in tree. Returns NULL if not found.
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* @param rbtree: tree to find in.
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* @param key: key that must match.
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* @return: node that fits or NULL.
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*/
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rbnode_type *rbtree_search(rbtree_type *rbtree, const void *key);
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/**
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* Find, but match does not have to be exact.
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* @param rbtree: tree to find in.
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* @param key: key to find position of.
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* @param result: set to the exact node if present, otherwise to element that
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* precedes the position of key in the tree. NULL if no smaller element.
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* @return: true if exact match in result. Else result points to <= element,
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* or NULL if key is smaller than the smallest key.
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*/
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int rbtree_find_less_equal(rbtree_type *rbtree, const void *key,
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rbnode_type **result);
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/**
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* Returns first (smallest) node in the tree
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* @param rbtree: tree
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* @return: smallest element or NULL if tree empty.
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*/
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rbnode_type *rbtree_first(rbtree_type *rbtree);
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/**
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* Returns last (largest) node in the tree
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* @param rbtree: tree
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* @return: largest element or NULL if tree empty.
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*/
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rbnode_type *rbtree_last(rbtree_type *rbtree);
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/**
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* Returns next larger node in the tree
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* @param rbtree: tree
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* @return: next larger element or NULL if no larger in tree.
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*/
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rbnode_type *rbtree_next(rbnode_type *rbtree);
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/**
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* Returns previous smaller node in the tree
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* @param rbtree: tree
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* @return: previous smaller element or NULL if no previous in tree.
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*/
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rbnode_type *rbtree_previous(rbnode_type *rbtree);
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/**
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* Call with node=variable of struct* with rbnode_type as first element.
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* with type is the type of a pointer to that struct.
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*/
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#define RBTREE_FOR(node, type, rbtree) \
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for(node=(type)rbtree_first(rbtree); \
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(rbnode_type*)node != RBTREE_NULL; \
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node = (type)rbtree_next((rbnode_type*)node))
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/**
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* Call function for all elements in the redblack tree, such that
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* leaf elements are called before parent elements. So that all
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* elements can be safely free()d.
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* Note that your function must not remove the nodes from the tree.
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* Since that may trigger rebalances of the rbtree.
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* @param tree: the tree
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* @param func: function called with element and user arg.
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* The function must not alter the rbtree.
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* @param arg: user argument.
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*/
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void traverse_postorder(rbtree_type* tree, void (*func)(rbnode_type*, void*),
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void* arg);
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#endif /* UTIL_RBTREE_H_ */
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